基于梁-梁与梁-表面接触公式的编织神经血管血流分流器力学建模
Mechanical Modeling of Braided Neurovascular Flow Diverters using a Beam-to-Beam and Beam-to-Surface Contact Formulation
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中文总结 AI 辅助
本研究提出基于梁-梁与梁-表面接触公式的编织神经血管血流分流器力学建模框架，经拉伸、径向压缩等典型案例验证，可用于分析其力学响应与几何特性。
中文摘要 AI 辅助
编织神经血管血流分流器广泛用于颅内动脉瘤的血管内治疗，其力学响应与最终展开构型由大量细长交织金属丝的相互作用决定。这类装置的准确数值建模对分析其在压缩或展开变形过程中的结构行为至关重要。本研究提出一种基于结构力学的建模框架与有限元公式，用于编织血流分流器的数值模拟：采用几何精确的Simo-Reissner梁理论对单根金属丝建模，可一致描述大转动与弯曲参考构型；通过梁-梁接触公式描述金属丝间的力学相互作用，通过梁-表面接触公式捕捉其与微导管等周围管状结构的相互作用；引入编织血流分流器几何的灵活参数化描述，可系统控制金属丝数量、编织角、装置长度、径向交织模式等几何设计参数。采用文献中的三个典型验证案例评估该框架：通过拉伸试验研究装置的长径关系与轴向力响应，通过径向压缩试验研究压力-直径行为，通过逐步压缩实例评估局部金属丝间距、螺距角、孔隙率与金属覆盖率等几何敏感量。这些基于结构力学与接触力学的案例，为所提建模框架及其在编织血流分流器力学分析中的应用提供了系统的验证场景。
英文摘要
Braided neurovascular flow diverters are widely used for the endovascular treatment of intracranial aneurysms, where their mechanical response and final deployed configuration are governed by the interaction of many slender, interwoven wires. Accurate numerical modeling of these devices is essential for analyzing their structural behavior during deformation occurring in compression or deployment. This work presents a structural-mechanics-based modeling framework and finite element formulation for the numerical simulation of braided flow diverters. The individual wires are modeled using geometrically exact Simo--Reissner beam theory, allowing a consistent description of large rotations and curved reference configurations. Mechanical interactions between individual wires are described by a beam-to-beam contact formulation, while the interaction with surrounding tubular structures, such as microcatheters, is captured by a beam-to-surface contact formulation. A flexible parametric description of interwoven braided flow diverter geometries is introduced, enabling systematic control of geometric design parameters such as wire count, braiding angle, device length, and radial interweaving pattern. The proposed framework is assessed by means of three representative validation cases from the literature. A tensile test is considered to investigate the length--diameter relation and axial force response of the device, while a radial compression test is used to study the pressure--diameter behavior. Finally, a stepwise compression example is used to evaluate geometry-sensitive quantities, including local wire distance, pitch angle, porosity, and metal coverage ratio. Rooted in structural mechanics and contact mechanics, these examples provide a systematical validation setting for the proposed modeling framework and its application to the mechanical analysis of braided flow diverters.
